Tamias cinereicollisgray-collared chipmunk

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Geographic Range

Tamias cinereicollis is found all throughout central and eastern Arizona and central and southwest New Mexico in the United States (Findley, 1986; Nowak, 1991).

Habitat

These chipmunks are found primarily in coniferous forests at elevations between 1,950 abd 3,440 meters. They prefer mature woodlands and woodlot edges, but they also inhabit areas in and around suburban and rural homes such as around ornamental plantings, rockpiles, outbuildings and below patios and building foundations. Although they are mostly burrowing rodents, they regularly climb oak trees to gain access to rooftops (Best, 1999; Corrigan, 1997; Grzimek, 1990; Sheppard, 1990).

  • Range elevation
    1,950 to 3,440 m
    to ft

Physical Description

Tamias cinereicollis are easily recognized by the light and dark stripes on their back and head. They bear distinct facial markings and have only five dark stripes on their back. There is a distinct central line that extends forward onto the head. The gray-collared chipmunks are covered in shades of gray and share distinctive patterns of black, pale gray, and buff stripes. Tamias cinereicollis is one of the smaller chipmunks. It has a total length between 208 and 242 mm, with males measuring slightly smaller than females. Weights range between 55 and 70 g. It has a relatively long tail, comprising from 90 to 109 mm of the total length of the animal (Best, 1999; Grzimek, 1990; Sheppard, 1990).

  • Sexual Dimorphism
  • female larger
  • Range mass
    55 to 70 g
    1.94 to 2.47 oz
  • Range length
    208 to 242 mm
    8.19 to 9.53 in

Reproduction

Mating occurs two times a year, during early spring and again during the summer or early fall. There is a 30 to 31 day gestation period. Two to five young are born in the spring (early May) and again between August and October. They are born naked and blind. Young can eat solid foods by the age of 36 to 40 days, and are weaned by the age of 41 to 45 days. The young are sexually mature within one year and adults may live for up to three years. Young appear for the first time above ground when they are 2/3 full size. The babies are reared by the mother without any help from the fathers (Best, 1999; Corrigan, 1997; Sheppard, 1990).

  • Breeding interval
    These animals usually breed twice yearly.
  • Breeding season
    This species breeds in the spring as well as in summer or early fall.
  • Range number of offspring
    2 to 5
  • Average gestation period
    30-31 days
  • Range weaning age
    41 to 45 days
  • Average time to independence
    45 days
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

Behavior

Tamias cinereicollis is most active during the early morning and late afternoon. These chipmunks are generally solitary and protect their territories except during courtship, or when the young are developing. Populations of chipmunks average between 2 and 4 animals per acre. The home ranges often overlap among individuals, and the home ranges of adults are larger than those of juveniles. The home ranges of females tend to be smaller than those of males.

With the onset of cold weather, chipmunks enter a restless hibernation during late fall or early winter and are relatively inactive during the winter months. Some individuals, however, occasionally come out on warm, sunny days during the winter. By early March, most gray-collared chipmunks have emerged from hibernation.

Male T. cinereicollis are the first to emerge in the spring. The females emerge one or two weeks later. Once females emerge, breeding takes place near a female's burrow. Competition occurs between males for females, and a male may mate with more than one female during a mating season.

The burrows of T. cinereicollis are well-hidden near buildings (such as basements and garages), gardens, stumps, woodpiles or brushpiles. The burrow entrance is usually about 2 inches in diameter. There are no obvious mounds around the burrow entrance because these chipmunks carry the dirt in their cheek pouches and scatters it on the ground away from the burrow to make the burrow entrance less conspicuous.

A chipmunk's main tunnel is between 20 and 30 feet in length, but complex burrowing systems occur where cover is sparse. Burrow systems normally include a nesting chamber, one or two food storage chambers, various side pockets connecting to the main tunnel, and separate escape tunnels.

(Corrigan, 1997; Sheppard, 1990).

  • Range territory size
    3.33 (high) m^2

Home Range

The average territory of a chipmunk is about 1/4 to 1/2 acre, but an adult usually only defends an area about fifty feet around the burrow entrance (Corrigan, 1997; Sheppard, 1990).

Communication and Perception

Food Habits

Tamias cinereicollis spends much of its day collecting and storing seeds, which are its most important source of food. These chipmunks often forage on the ground and they easily climb trees and shrubs to harvest nuts and fruits.

The diet of T. cinereicollis consists of various kinds of nuts, berries, and seeds. Mushrooms, cherry and plum pits, insects, worms and carrion are also consumed. Rare instances of T. cinereicollis preying on birds or small mammals have been observed.

When these chipmunk prepare food for storage, they holds the seeds in their dexterous front paws and with their specialized incisors. Their incisors are especially long and directed forward. Tamias cinereicollis removes seeds from pods with its incisors, then uses its tongue to shift the seeds backward. It stuffs the seeds between its teeth and inside of its cheekpouches. The capacity of these cheekpouches increases with maturity. When they cheek pouches are full, a chipmunk deposits the seeds in its nest or buries them in shallow holes.

After hibernation, gray-collared chipmunks diligently search the ground for any seeds that remain from the previous summer. Since these are usually uncommon, T. cinereicollis may eat young leaves and shoots until new fruit and seeds become available (Corrigan, 1997; Schultz, 1995; Sheppard, 1990).

  • Animal Foods
  • birds
  • mammals
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts

Predation

Predators include as hawks, weasels, coyotes, martens, foxes, and snakes. Fighting during the breeding season is also a source of injury and death for many gray-collared chipmunks.

The most significant decrease in T. cinereicollis populations occurs during periods of food shortage such as when there is seed crop failure and the chipmunk doesn't have enough food stored for its hibernation. Tamias cinereicollis depends on this food during the winter when it doesn't have access to seeds that are covered by snow, etc. (Shepppard, 1990).

Ecosystem Roles

Since chipmunks prey upon insects, their food habits influence the growth of various plants. Gray-collared chipmunks are also important in the dispersal of seeds because of their habit of storing them beneath the layer of decaying vegetation on the forest floor. In this way, T. cinereicollis assist in the spread of shrubs, trees, and other plants. As a prey species, populations of T. cinereicollis may have some impact upon predator populations. (Corrigan, 1997; Sheppard, 1990).

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

These animals are not reported to have a positive impact on human economies.

Economic Importance for Humans: Negative

Chipmunks can be serious destructive pests when they become numerous around homes and gardens. The burrowing activity of chipmunks can cause significant structural damage by undermining foundations, concrete patios and steps, retaining walls and sidewalks. They may also be destructive to gardens when they dig up and eat bulbs and seeds or attack garden fruits. When they become over-abundant, gray-collared chipmunks can prevent normal reforestation of some trees, especially pines, by eating their seeds. When this occurs, they have to be trapped by humans.

Rodents, such as T. cinereicollis, have also been associated as being carriers of the hantavirus in the southwestern United States. Human infection may occur when infective saliva or excreta are inhaled as aerosols produced directly from the animal. Persons have also become infected after being bitten by rodents (Corrigan, 1997; Healthtouch, 1997; Sheppard, 1990).

  • Negative Impacts
  • injures humans
    • bites or stings
    • carries human disease
  • crop pest
  • household pest

Conservation Status

Gray-collared chipmunks are not in any danger of going extinct any time soon. In fact, this species experiences only tiny fluctuations in its population from year to year. These fluctuations have been attributed to predators such as hawks, weasels, coyotes, martens, foxes, and snakes. Fighting during the breeding season is also a source of injury and death for many gray-collared chipmunks.

The most significant decrease in T. cinereicollis populations occurs during periods of food shortage such as when there is seed crop failure and chipmunks doesn't have enough food stored for hibernation. T. cinereicollis depends on stored food during the winter when it doesn't have access to seeds that are covered by snow, etc. (Shepppard, 1990).

Other Comments

Gray-collared chipmuinks, along with many other chipmunks, have charming personalities. They charm campers and hikers with their small size, their boldness in search of food, and their constant activity. In fact, they are not hard to approach at all. They are easily persuaded to accept seeds or nuts from a person's hands (Sheppard, 1990).

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Candace T. Smith (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Corrigan, R. "Chipmunks." Purdue University. http://www.entm.purdue.edu/entomology/urbancenter/pubs/chips.html (1 Dec. 1997)

Findley, J.S. 1987. The Natural History of New Mexican Mammals. University of New Mexico Press, Albuquerque.

Grzimek, B. 1990. Encyclopedia of Mammals. McGraw-Hill Publishing, Co. Vol 3. pp. 78-82

"Hantavirus Infection-Southwest United States." Healthtouch Online. http://www.healthtouch.com/level1/leaflets/cdc/cdc016.htm (1 Dec. 1997)

Nowak, R.M. 1991. Walker's Mammals of the World. Fifth Edition. Johns Hopkins University Press, Baltimore. pp. 586-589

Sheppard, D. 1990. "Chipmunk." Canadian Wildlife Service Hinterland Who's Who. http://www.ec.gc.ca/cws-scf/hww-fap/chipmunk/chipmunk.html (1 Dec. 1997)

Best, T. 1999. Gray-collared chipmunk (Tamias cinereiollis). Pp. 362-363 in D Wilson, S Ruff, eds. The Smithsonian Book of North American Mammals. Washington and London: The Smithsonian Institution Press.